Megger BMM500 User Manual

M

Megger Limited
Archliffe Road, Dover
Kent CT17 9EN England
T [phone]
F [phone]

Megger
PO BOX 9007, Valley Forge
PA 19484-9007 USA
T [phone]
F [phone]

Megger
4271 Bronze Way, Dallas, Texas
75237-1017 USA
T [phone]
T [phone]
F [phone]

Megger SARL
29 Allée de Villemomble
93340 Le Raincy, France
T +33 (1) 43.02.37.54
F +33 (1) 43.02.16.24

OTHER TECHNICAL SALES OFFICES
Toronto CANADA, Mumbai India and BAHRAIN.

Megger products are distributed in 146 countries worldwide.

This instrument is manufactured in the United Kingdom.
The company reserves the right to change the specification or design without prior notice.

Megger is a re g i s t e red trademark

Part No. 6172-697 V02 Printed in England 11HH
www.megger.com

USER GUIDE

GUIDE D’UTILISATEUR

BENUTZERANLEITUNG

GUÍA DEL USUARIO

M

BMM500 Series
Insulation & continuity testers

Contents

Safety Warnings 2
Description 3
Operation 4

Live Circuit warning 4
Voltage testing 4
Auto-shut off 4
Backlight 4
Insulation tests 5
Locking Test Button (ltb) 5
Polarisation Index Te s t i n g 5
Automatic Discharge 6
Zeroing of Test Lead Resistance 7
Possible sources of error 7
Continuity Bleeper 8
Resistance Tests (kΩ) 8
Diode Te s t i n g 8
Voltage Tests (V) 9
Battery Replacement 10
Fuse Checking and Replacement 10
Using the MEGGER SP1
Switched Probe 11

Specification 12

Repair and Warranty 19

1

Symbols used on the instruments are :

Caution, risk of electric shock.

Caution, refer to User Guide.
Equipment protected throughout

by Double Insulation (Class II).
Equipment complies with
current EU Directives.
Equipment must not be
connected to voltage sources
>600V CAT II. Suitable for
electrical installations CAT III
300V to Earth

>600V

2

SAFETY WARNINGS

• Safety Warnings and Precautions must be read and understood before the instrument is used. They
must be observed during use.

• The circuit under test must be de-energised and isolated before connections are made except for
voltage measurement.

• Circuit connections m u s t not be touched during a test.

• After insulation tests, capacitive circuits must be allowed to discharge before disconnecting the test

leads.

• The Live Circuit Warning and Automatic Discharge are additional safety features and should not b e
regarded as a substitute for normal safe working practice.

• Replacement fuses m u s t be of the correct type and rating. Failure to fit the correctly rated fuse will result
in damage to the instrument in the event of an overload.

• Test leads, including crocodile clips, must be in good order, clean and have no broken or cracked
i n s u l a t i o n .

• Ensure that hands remain behind guards of probes/clips when testing.

• U.K. Safety Authorities recommend the use of fused test leads when measuring voltage on high energy

s y s t e m s .

NOTE

THE INSTRUMENTS MUSTONLY BE USED BYSUITABLY TRAINED AND COMPETENTPERSONS

Users of this equipment and/or their employers are reminded that Health and Safety Legislation require them to carry out valid risk assessments

of all electrical work so as to identify potential sources of electrical danger and risk of electrical injury such as from inadvertent short circuits.

Where the assessments show that the risk is significant then the use of fused test leads constructed in accordance with the HSE guidance note

GS38 ‘Electrical Test Equipment for use by Electricians’ should be used.

Description

Congratulations on your purchase of a genuine
Megger insulation/continuity tester. Megger has
over 100 years experience in insulation testing
which is reflected in its product designs. Your
BMM500 has been carefully developed to
address the real needs and benefits of the user.

The Megger BMM500 Series instruments are
battery powered Insulation and Continuity
testers, with a measurement capability from
0,01Ω Continuity to 10GΩ Insulation.

O ffering multi-voltage facilities, the instruments
take full advantage of microprocessor t e c h n o l o g y
and feature a large liquid crystal display
combining digital and analogue readings. T h e
analogue display has the benefit of indicating
trends and fluctuations in readings, while the
digital readout gives direct accurate results. T h e
display is also backlit giving clear visibility even
in low light conditions.

The BMM500 Series instruments have the
unique capability of being able to measure
voltages down to a resolution of 0,1mV. This

gives the user the option to fit a wide variety of
transducers to further enhance the capabilities
of the BMM Series instruments, eg temperature
or humidity measurement.

A customised connector on the top of the
instrument enables the optional Megger SP1
Switched Probe to be used for two handed
probe operation.

The 250V, 500V and 1000V ranges can be
used to test electrical installations in compliance
with BS7671 (16th Edition IEE Wi r i n g
Regulations) IEC364 and HD384, since each
range has a 1mA minimum test current at the
minimum pass values of insulation specified in
these documents. Designed to IEC1010-1 the
BMM500 Series are protected against
connection to a 300V Category III supply. T h e
instruments have a basic accuracy of ±2% at
20°C. The instruments are waterproof and
dustproof to IP54. This helps maintain accuracy
and ensures maximum reliability in harsh
e n v i r o n m e n t s .

3

Operation

Refer to Safety Wa rnings before using
the instrument

Testing is automatically inhibited if:

• An external voltage >55V is present when
switched to any insulation range position

• An external voltage >10V is present on all
other ranges (excluding OFF/V).

The external voltage is indicated on the display,
on insulation ranges an audible bleeper will
sound if a test is attempted.

Live Circuit Wa rn i n g

When more than 25V is applied to the terminals
in the insulation ranges, the instrument defaults
to a voltmeter and gives an audible warning.
On all other switch positions except OFF/V
when approx 10V is applied the default
voltmeter will be activated. Testing will be
inhibited.

Voltage Testing on High Energy Systems

Use extreme care when using or measuring
voltages above 30V, particularly in high energy

systems. Fused test leads are available as
optional accessories for local situations where
increased protection is required.

Auto-shut Off

To conserve battery life, Auto-shut Off (preceded by
a series of bleeps) operates after approx.
10 minutes of instrument inactivity on
insulation, 5 minutes on all other ranges. If the
instrument is switched on whilst holding the

key, the Auto shut-off time is extended to
60 minutes. To restore operation after Auto­shut Off, select OFF followed by the required
switch position.

Note: It is recommended that the instrument is

switched to the OFF position when not

in use.

B a c k l i g h t

The backlight is activated by pressing the

key.The backlight will remain illuminated
for approx. one minute before automatically
switching off to conserve battery life,

4

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